Restrictor means for heat pump system



Oct. 8, 1968 s. s. FINEBLUM RESTRICTOR MEANS FOR HEAT PUMP SYSTEM Filed March 2, 1967 INVENTOR.

SOLOMON .5. F/A/EBL UM 47' 7' ORWEYS United States Patent r 3,404,542 RESTRICTOR MEANS FOR HEAT PUMP SYSTEM Solomon S. Finehlum, Silver Spring, Md., assignor to Ranco Incorporated, Franklin County, Ohio, a corporation of Ohio Filed Mar. 2, 1967, Ser. No. 620,045 4 Claims. (Cl. 62-324) ABSTRACT OF THE DISCLOSURE A heat pump system is shown comprising a compressor and two heat exchangers connected in a refrigerating circuit including a refrigerant flow restricting means between the exchangers which imparts relatively high restriction to the flow of refrigerant from one exchanger to the other exchanger and a relatively lower restriction to the flow of refrigerant in the oppoiste direction. A reversing valve is arranged to reverse the order of flow of refrigerant through the two exchangers. The flow restricting means comprises a cylindrical chamber having an opening in one end wall thereof connected to the exchanger and a nozzle member opening in the side wall of the chamber with the axis thereof extending substantially tangentially to the circular walls of the chamber. The nozzle member is connected to one exchanger. When the flow of refrigerant is from the one exchanger to the other exchanger, the nozzle imparts a swirl or vortex effect to the refrigerant in the chamber and the passage of the refrigerant into the opening is restricted. When the flow of refrigerant is from the other exchanger to the one exchanger, the refrigerant passes from the opening into the nozzle with but slight restriction or impedance.

The present invention relates to restrictor means for heat pumps of the type comprising a compressor-condenser-evaporator refrigerating system in which a refrigerant is compressed by the compressor, condensed in a heat exchanger designated as a condenser, and is then passed through a restrictor to a heat exchanger which serves to evaporate the condensed refrigerant and in so doing absorb heat from the walls of the heat exchanger, after which the evaporized refrigerant is returned to the intake of the compressor.

Heretofore, it has been common practice to provide heat pump systems of the type referred to which include means for reversing the order of flow of refrigerant from the compressor through the two heat exchangers so that the functions of the heat exchangers are reversed. Thus, one of the exchangers is adapted to heat or cool the air of a room, for example, according to the order of flow of refrigerant. When the order of flow of refrigerant is reversed, it is necessary to alter the degree of restriction between the two heat exchangers to provide for proper operation of the system in the alternative function, as is well understood in the art. The means heretofore employed to provide the most efiicient restriction for the particular flow of refrigerant have been relatively expensive and complicated. The principal object of the present invention is the provision of an extremely simple and inexpensive, yet effective, means to produce a relatively high restriction to the flow of refrigerant from one heat exchanger to the other during the cooling cycle, and to produce a substantially lesser degree of restriction when the refrigerant flow is in the opposite direction between the exchangers during the heating cycle.

In carrying out the invention the refrigerant passage between the two heat exchangers includes a cylindrical chamber having a refrigerant passage in an end wall thereof and disposed in a plane extending transversely of the axis of the chamber, the chamber having a conduit 3,404,542 Patented Oct. 8, 1968 opening tangentially into the circular wall of the chamber so that when refrigerant flows into the chamber through the axially aligned opening the refrigerant flow out of the tangentially arranged conduit is relatively unrestricted, whereas when the order of flow of refrigerant through the exchangers is reversed, the refrigerant entering the tangentially arranged opening has a swirling motion or vortex imparted thereto in the cylindrical chamber, which vortex restricts the flow of the refrigerant from the chamher through the axially aligned opening.

Other objects and advantages of the invention will be apparent from the following description of a preferred form thereof, reference being made to the accompanying drawings wherein:

FIG. 1 is a schematic view of a heat pump system embodying the invention;

FIG. 2 is a longitudinal sectional view of a refrigerant flow restricting means embodied in the heat pump system shown in FIG. 1, the view taken substantially along line 2-2 of FIG. 3; and

FIGS. 3 and 4 are sectional views taken substantially along line 3-3 of FIG. 2. with arrows indicating the type of refrigerant flow which occurs when the direction of refrigerant flow through the system is reversed.

Referring to FIG. 1, a conventional compressor-condenser-expander type of heat pump system is shown which includes a suitably power-driven compressor 10 which discharges compressed refrigerant into a conduit 11 connected with the inlet of a reversing valve V. The valve V has one port thereof connected by a tube or conduit 16 to a heat exchanger 17 which comprises the tube 16 formed in a series of serpentine coils or loops supported at opposite ends by suitable plates 18, only one of which appears in the drawings. Preferably, the tube 16 is copper so that rapid heat exchange is provided between the refrigerant flowing through the tube and the air surrounding the coiled tube. The tube 16 is connected to a coupling tube 20 of a refrigerant restrictor means 21. The restrictor means 21 is connected with the end section of a copper tube 22, the principal portion of which is formed in serpentine coils supported by spaced end plates 26, only one of which appears in the drawings, and which forms a heat exchanger 27 similar to the exchanger 17. The opposite end section of the tube 22 is connected to one of the ports of the four-way va'lve V. The outlet port of the valve V is connected by a pipe 30 to the suction side of the compressor 10.

The reversing valve V may be of any suitable type and in the form shown includes a solenoid 31 which is adapted to be energized by power lines L-l, L-2 through a switch 32. The switch 32 may be any suitable type, such as a thermostatic switch responsive to the temperature of a room, not shown, the air of which room is tempered by the exchanger 27. When the solenoid 31 is deenergized the valve ports of the valve V are positioned so that the flow of refrigerant is from the compressor 10, through conduit 11, valve V, tube 16, heat exchanger 17, restrictor means 21, heat exchanger 27, valve V, and pipe 30 to the compressor. During this cycle or phase of operation the heat exchanger 17 serves as a condenser and gives up heat to atmospheric air which is passed over the exchanger by a blower or the like, not shown, as is well known in the art. The flow of refrigerant from the exchanger 17 to the exchanger 27 is restricted by the restricting means 21 so that a substantially lower pressure is maintained in the exchanger 27 than in the exchanger 17, causing evaporation of the refrigerant and chilling of the exchanger 27. Air from the room to be tempered is forced over the exchanger 27 by a blower, not shown, and returned to the room in a conventional fashion to cool the room.

When the solenoid 31 is energized by closing of the switch 32, the ports of the valve V are shifted so that the order of flow of refrigerant through the exchangers 17, 27 is reversed, that is to say, the flow is from the compressor 10, through conduit 11, valve V, exchanger 27, restrictor means 21, exchanger to valve V, and pipe 30 to the suction side of the compressor. During this phase of operation of the system, the heat exchanger 27 serves as the condenser and the heat thereof is given up to the room air. The exchanger 17 now functions as the evaporator and absorbs heat from the atmospheric air passed thereover. As is well understood in the art, considerably less restriction to the flow of refrigerant from the exchanger 27 to the exchanger 17 is required because the temperature of the room air passed over the exchanger 27, which now serves as the condenser, is relatively higher than the temperature of the relatively cooler atmospheric air passed over the exchanger 17, which now serves as the evaporator. Accordingly, the restrictor means 21 functions to provide substantially less restriction to the flow of refrigerant in the direction of refrigerant flow therethrough just described.

Although not shown, it may be desirable to provide means by which an additional volume of refrigerant is circulated in the system during the cycle in which the exchanger 27 serves as the condenser. Such means are known and the disclosure thereof in this application is not necessary to an understanding of the invention.

Referring to the construction of the restrictor means 21, a drum-shaped chamber 34 is formed by a cup-shaped member 35 having its open end closed by a circular wall 36 which is suitably brazed in place, and the opposite end wall 37 of the member 35 has an opening 38, the circular Walls of which are coaxial with the circular walls of the chamber. A coupling sleeve 40 is formed integral with the wall 37 and is coaxial with the opening 38. The sleeve 40 receives an end portion of the tube 22 which is brazed in the sleeve. An opening 41 is formed in the circular side wall of the chamber 34, and a flattened end portion of the coupling tube 20 is brazed in the opening 41 and forms a relatively Wide, flat jet-like nozzle 42, the axis of which is substantially tangential to the inner cylindrical walls of the chamber 34. The flattened nozzle 42 extends the length of the chamber 34. Thus, refrigerant directed into the chamber 34 through the nozzle 42 produces a vortex or swirl, as indicated by the arrows in FIG. 3. The vortex restricts the ability of the refrigerant to exit the chamber through the axial opening 38, and consequently, a relatively high degree of restriction is imposed to the flow of refrigerant from the exchanger 17 to the exchanger 27.

When the valve V is operated to establish a cooling cycle, that is, with the flow of refrigerant from the compressor 10 to the heat exchanger 27 and then to the exchanger 17, refrigerant enters the chamber 34 through the tube 22. Because the axis of tube 22 and the walls of the opening 38 are coaxial with the cylindrical Walls of the chamber 34, the refrigerant entering the chamber is dispersed in radial directions as indicated by the arrows in FIGS. 2 and 4, and passes into the nozzle 42 with considerable less restriction to its flow than when refrigerant passes through the restricting means 21 in the opposite direction. The restriction to the flow of refrigerant from the exchanger 27 to the exchanger 17 may be determined principally by the diameter of the opening 38.

The diameter of the axial opening 38 should be selected so as to provide the proper restriction for flow during the heat cycle. The degree of restriction imposed on the refrigerant flow during the cooling cycle is affected by the diameter and length of the cylindrical chamber 34. The optimum dimensions of the opening 38, diameter and length of the chamber 34 and the form of the opening of the nozzle 42 can be readily determined by trial, depending upon the capacity of the particular system.

It is obvious that the restrictor means 21 of exceedingly simple design and, having no moving parts, is inexpensive, durable and efficient in imposing different restrictions to the flow of refrigerant in opposite directions thereby providing optimum performance for heat pump systems of the type mentioned at low cost.

Although but one form of the invention has been described, it is to be understood that other forms, modifications and adaptations thereof may be made, all falling within the scope of the claims which follow.

I claim:

1. In a heat pump system comprising a compressor and tWo heat exchangers connected in a refrigerating circuit and having refrigerant flow restricting means between said exchangers, characterized by said flow restricting means comprising a chamber having an opening in one end wall thereof, a nozzle member opening in a side wall of said chamber, the axis of said nozzle member lying in a plane extending transversely of the axis of said opening in said one end wall and disposed laterally from the axis of said opening, means connecting said opening to one of said exchangers and connecting said nozzle member to the other of said exchangers for establishing a flow of refrigerant through said chamber during refrigerating cycles, and means to reverse the order of flow of refrigerant through said exchangers.

2. In a heat pump system as set forth in claim 1 further characterized by said chamber being cylindrical.

3. In a heat pump system as set forth in claim 2 further characterized by the axis of said nozzle being directed substantially tangentially into said chamber.

4. In a heat pump system as set forth in claim 3 further characterized by said nozzle extending substantially the length of said chamber.

References Cited UNITED STATES PATENTS 2,694,296 11/1954 Prosek 625ll XR MEYER PERLIN, Primary Examiner. 

